<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			//string --> number
			var s1 = "1";
			console.log(s1 + 2);
			var num1 = parseInt(s1);
			var num2 = s1 - 0;
			var num3 = Number(s1);
			console.log(num2 + 2)

			//number --> string
			var n1 = 6;
			console.log(typeof n1);
			var s2 = n1 + "";
			console.log(typeof s2);
			var s3 = n1.toString();
			console.log(typeof s3);
		</script>
	</head>
	<body>
	</body>
</html>
